齿轮轴系弯扭耦合振动理论的统一

在研究齿轮轴系的弯扭耦合振动时,有两种常用的耦合模型,即力耦合模型和几何耦合模型。本文证明,这两种耦合模型以及基于这两种耦合模型构建的齿轮轴系弯扭耦合振动方程可以被统一到一个统一的模式中;几何耦合模型是力耦合模型的特例,几何耦合模型及基于几何耦合模型的齿轮轴系弯扭耦合振动方程可分别从力耦合模型及基于力耦合模型的齿轮轴系弯扭耦合振动方程中导出,从而大大方便和简化了用几何耦合模型构建齿轮耦合轴系弯扭耦合振动方程的过程。对这两种耦合模型进行的数值计算与分析表明,在进行齿轮耦合轴系转子动力学研究时,几何耦合模型和力耦合模型具有相同的效果,而且力耦合模型中齿轮啮合刚度的取值对计算结果几乎没有影响。     

空气静压轴系支承的数值分析

采用有限差分技术,对精密轴系中的径向和轴向空气静压轴承进行了数值分析。主要针对有多个供气孔的径向轴承的复杂流场,沿周向展开承载曲面以雷诺方程为气体润滑的控制方程。同时根据质量守恒原理,制定出每个供气孔出口压力边界条件逐轮修正的迭代路线,计算出不同偏心率和供气压力下的压力分布、承载能力及流量。该技术成功地用于轴系支承精确设计并制造出精密模块化主轴轴系。     

存稿文摘

3.39微米氮氖激光器的研制煤炭部抚顺研究所杜继祥等本文介绍了3.39微米低噪声氦氖激光器,它具有制造容易、放电稳定、耗散功率小,腔内热变化较小等特点;并指出了该激光器的稳定性措施、工艺要点、延长寿命问题、工作特性和低噪声特性等。图2表4,参9。精密双球轴系的加工新天精密光学仪器公司赵德甫本文介绍了两秒级分度头双球轴系的结构,几何精度及其对使用的影响。该轴系的摆动量为0.00035mm,装入60℃锥面后,测量轴系的径向综合跳动量为0.002mm。本文对工艺分析及精加工工艺设计,进行了详细论述。指出     

磁盘、磁头飞行特性测试仪中的空气静压精密轴系研制

磁盘、磁头飞行特性测试仪是检测磁盘盘面特性、磁头飞行特性及其飞行间隙的专用设备,而空气静压精密轴系是该设备的关键部件。本文着重对空气静压精密轴系的结构设计及其静态性能、动态性能测试作了较详细的论述,通过理论与实验对比,验证设计的合理性和计算的正确性。尤其是在实验的基础上建立了轴系角刚度理论数学模型和实验数学模型,为研究轴系角刚度提供了理论与实验依据。     

圆锥形精密滚动轴系的设计与计算

本文结合实例介绍了一种新型精密回转轴系的设计与计算,推导了轴系在纯滚动无滑动运动条件下的结构参数计算公式。实践证明,这种轴系结构简单、加工容易、对中性好、回转精度高,可在精密仪器设计中推广采用。     

SK-21数控凸轮磨床几何误差补偿技术的理论研究

针对如何减小SK-21数控凸轮磨床的几何误差从而提高加工精度，以多体系统运动学理论为基础，根据自身结构和运动误差，推导出凸轮精密加工的计算方程；明晰了精密数控指令的迭代求解过程；分析了刀具理想与实际路线的计算方法，内外法线的判定和曲线的拟舍方法；并从解析几何理论和多体系统理论两个不同角度对几何误差参数辨识进行了讨论。     

精密轴系中转轴的刚度计算与尺寸确定

转轴是精密轴系的核心件。本文介绍了立式精密轴系中转轴的刚度计算与其尺寸确定的方法。     

电主轴动力学分析的传递矩阵法

介绍了电主轴的结构特点,利用传递矩阵法将其简化并进行分段建模,对轴系中典型单元的状态进行了教学描述.针对电主轴的特殊结构,修改了简化模型中部分典型单元的状态向量,得到电主轴的传递矩阵方程(即轴系的频率方程),并以某型号电主轴为例,计算轴系的固有频率和临界转速.同时用有限元分析软件ANSYS建立了电主轴实例的三维模型,并进行模态分析,得到轴系的固有频率和一阶振型,与传递矩阵方程的计算结果基本吻合.这表明所提出的时电主轴轴系频率方程的修改是可行的,而且更接近实际情况,对电主轴的动力学分析有重要的参考价值.     

大型透平机组轴系扭曲临界转速的计算方法

介绍了用霍尔茨(Holzer)法计算复杂轴系扭曲临界转速的具体简化方法,列举出几种典型几何结构的等效直径计算公式。用此方法编写的计算机程序可以计算任何一个大型复杂轴系。     

温度和过盈量对轴系接触应力及刚度性能的影响

航天特种装备在轨服役期间故障因素和演化规律是研究航天器可靠性的重要基础方向。精密轴系性能随恶劣空间环境的变化而发生演变。轴承固体润滑膜的接触应力和轴系的刚度性能对于精密轴系精确、可靠运行具有重要意义。以航天机构中驱动单元轴系的成对角接触球轴承为研究对象,考虑环境温度、热致过盈量和轴向载荷,分析了在交变温度作用下轴系的各组件在径向和轴向产生的热变形引起的配合表面配合性质和配合量的变化及成对角接触球轴承预紧特性的变化,提出了数值求解轴承接触应力和轴系刚度变化规律和变化范围的整体思路和分析框架,并进行了算例计算。计算思路具有普遍适用性,计算过程及结果对于驱动单元轴系的结构设计及可靠性验证试验的开展具有指导意义。     

Numerical simulation and experimental research on passive hydrodynamic bearing in a blood pump

The current research of hydrodynamic bearing in blood pump mainly focuses on the bearing structure design.Compared with the typical plane slider bearing and Rayleigh step bearing,spiral groove bearing has excellent performance in load-carrying capacity.However,the load-carrying capacity would decrease significantly with increasing flow rate in conventional designs.In this paper,the special treatment is made to the upper spiral groove bearing to make sure that both the circulatory flowing and load-carrying capacity are high.Three-dimensional computational fluid dynamics(CFD) models in the space between rotor and shaft are developed by using FLUENT software.Effects of groove number,film height and groove depth on load-carrying capacity of the spiral groove bearings are investigated by orthogonal experiment design.The experimental results show that film height is the most remarkable factor to the load-carrying capacity.The variation tendency of load-carrying capacity reveals that the best combination of geometry is the one with groove number of 8,film height 0.03 mm and groove depth 0.08 mm.The velocity and pressure distributions in spiral groove bearings are also analyzed,and the analysis result shows that the distributions are in conformity with the design of the blood pump based on the principle of hydrodynamic bearing.The displacement of the rotor with the best combination parameters is tested by using laser displacement sensors,the testing result shows that the suspending performance is satisfactory both in axial and radial directions.This research proposes a bearing design method which has sufficient load-carrying capacity to support rotor as an effective passive hydrodynamic bearing.     

精密多油楔动压轴系的楔形间隙参数与油膜运动稳定特性

针对精密仪器轴系的研制和精度分析,研究了立式三油楔动压轴系的结构、轴承轮廓结构,建立数学模型、分析模型,对轴系动压油膜的动力特性做了分析.对于主轴在动压油膜反力与外载荷作用下处于某一平衡位置(e,θb)运转时,能否经得起任意微扰动的干扰而失稳,建立了油膜运动稳定性的判据.应用数值模拟和计算机编程,深入研究了关键设计参数楔形间隙bm、cm相应的油膜运动稳定特性,揭示了楔形间隙值与轴系失稳的对应关系,给出了油膜稳定性因数Log(Sp)与偏心率ε(ε=e/c)之间的变化曲线图,并指出了楔形间隙参数最佳的取值范围.研究结果指出:楔形间隙是轴系设计和制造的重要敏感参数;最大楔形间隙bm和最小间隙cm值之间应保持一定的比例,否则油膜运动发散,轴系平衡失稳,导致主轴转动中产生较大的晃动.对于低速立式三油楔动压轴系,则bm-cm≥0.8 μm.比较研究结果与成功轴系实例,表明实例中bm、cm取得符合轴系的油膜稳定条件.证明研究结果对该类轴系的设计具有实用性.     

基于气穴模型的动压轴承动态油膜刚度计算方法

针对雷诺方程很难准确反映动压轴承高速转动过程中引起的周向惯性效应、动态挤压效应等的影响,进而导致油膜动态刚度计算精度难以满足高精度轴承设计的现状,提出用ADINA软件先求解瞬态油膜压力分布和瞬态油膜力,得到轴心轨迹,然后结合差分计算模型计算油膜动态刚度的方法。该计算方法基于流固耦合和气穴模型,定义油膜和轴的流固耦合时,采用任意的拉格朗日-欧拉(ALE)算法有效避免了油膜网格畸变的问题,再现轴心动态平衡过程和三维流场压力分布的动态发展过程,得到瞬态过程中的动态油膜力和动态油膜刚度。试验结果和基于流固耦合和气穴模型的计算结果对比分析发现两者基本吻合,说明该基于流固耦合和气穴模型的数值仿真计算方法是可行和有效的。     

内反馈水润滑高速动静压轴承的应用

针对水润滑高速动静压轴承承载力和刚度下降的问题,根据水润滑条件下,以静压承载为主的特点,在进行水润滑高速动静压轴承结构设计时,引入内反馈。通过数值模拟,证明在主承载区结构参数相同的情况下,采用内反馈后水润滑高速动静压轴承的承载力和刚度得到提高。试验表明,该设计方案对于提高水润滑高速动静压轴承的承载力和刚度效果明显。     

The use of sintered metal bearings for high sliding velocities

Results of investigations are discussed concerning the friction and wear behaviour of sliding bearings made by powder metallurgy. The aim of the work was to extend the use of such bearings up to speeds of 12 m/s. From the results obtained, selection guidelines were deduced for the practical use of such bearings under static and dynamic load and compiled in tables for the user. In addition to tribological investigations with conventional sintered bearings, the influence of changed geometry of the bearing bore on the running behaviour of such bearings was also studied, paying attention to the technological production variants. Using this design of bearings it is the aim of the work to create improved preconditions for the generation of partial hydrodynamic load-carrying portions, so decreasing the bearing temperature and, in turn, an increasing fatigue life and reliability. Furthermore, a measuring arrangement is introduced to determine the pressure in the lubrication gap. The measuring principle was evaluated by determining the pressure patterns of massive sliding bearings and comparing them with calculated pressure values. First results of measurements of the pressure build-up in conventional sintered bearings are discussed.     

客运索道托索轮深沟球轴承温度分析

托压索轮是客运索道线路中重要的支撑结构,其稳定运行对整个索道系统至关重要。托压索轮中使用的深沟球轴承由于索轮结构限制,散热条件不佳,在长时间连续运行后温度很容易升高,影响部件间的配合,文中通过计算轴承的发热量,在AnsysWorkbench中计算得到轴承在稳定状态下的温度,进而分析不同因素对轴承温升的影响,为了解轴承温度分布和合理选取设计参数提供参考。     

基于Pro/E的圆柱滚子轴承参数化结构设计

基于滚动轴承重复设计率高,以Pro/E的记录文本文件为软件开发的接口,开发了圆柱滚子轴承参数化结构设计软件。在轴承的外径、内径、宽度等基本尺寸确定后,软件将在外部数据库的支持下按照输入的设计参数确定内部几何结构尺寸参数、计算运动参数,最终实现圆柱滚子轴承三维造型和产品图的输出。开发过程简便易行,编程工作量小。     

Improvement of the computation procedure for complex-loaded sleeve bearings lubricated with non—newtonian oils

Computation results for the hydromechanic characteristics of a complex-loaded bearing with a Non-Newtonian oil and a geometry of the oil layer that is different from the ideal one are presented. The field of hydrodynamic pressures in the lubricant layer of the Non—Newtonian liquid was determined with the use of the algorithm of the conservation of mass (Elrod equation) and by integrating the Reynolds equation. The procedure can be used in the practice of the design of sleeve bearings.     

地铁轴承的设计与应用

根据地铁轴承的特殊工况要求,采用优化设计模型,对其内部结构参数进行优化设计,并利用AutoCAD软件的图形用户界面模块创建了用户界面。以某两面带密封罩的双列圆锥滚子轴承为例给出了计算公式。优化后轴承的额定载荷有了显著的提高,密封效果良好,优化公式可作为今后该类轴承设计的参考。     

The possibility of evaluating turbo-set bearing misalignment defects on the basis of bearing trajectory features

This paper presents the results of computer simulation of bearing misalignment defects in a power turbogenerator. This malfunction is typical for great multi-rotor and multi-bearing rotating machines and very common in power turbo-sets. Necessary calculations were carried out by the computer code system MESWIR, developed and used at the IFFM in Gdansk for calculating dynamics of rotors supported on oil bearings. The results are presented in the form of a set of journal and bush trajectories of all turbo-set bearings. Our analysis focuses on the vibrational effects of displacing the two most vulnerable machine bearings in horizontal and vertical directions by the maximum acceptable range calculated with regard to bearing vibration criterion. This assumption required preliminary assessment of the maximum values for the permissible bearing dislocations. We show the relations between the attributes of the particular bearing trajectories and the bearing displacements in relation to their base design position. The shape and dimensions of bearing trajectories are interpreted based on the theory of hydrodynamic lubrication of oil bearings. It was shown that the relative journal trajectories and absolute bush trajectories carry much important information about the dynamic state of the machine, indicating also the way in which bearings are loaded. Therefore, trajectories can be a source of information about the position and direction of bearing misalignments. This article indicates the potential of using trajectory patterns for diagnosing misalignment defects in rotating machines and suggests including sets of trajectory patterns to the knowledge base of a machine diagnostic system.